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Commit 0156b06a authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcl812: introduce pcl812_isadma_disable() 



According to Documentation/DMA-ISA-LPC.txt, the DMA lock needs to be
claimed before using any of the ISA DMA routines. Introduce a helper
function to disable the ISA DMA controller and add the necessary
locking calls.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1ec64b74

drivers/staging/comedi/drivers/pcl812.c

+11 −2
Original line number Diff line number Diff line
@@ -547,6 +547,15 @@ static void pcl812_isadma_program(unsigned int dma_chan, 
	release_dma_lock(flags);

}



static void pcl812_isadma_disable(unsigned int dma_chan)

{

	unsigned long flags;



	flags = claim_dma_lock();

	disable_dma(dma_chan);

	release_dma_lock(flags);

}



static void pcl812_start_pacer(struct comedi_device *dev, bool load_timers)

{

	struct pcl812_private *devpriv = dev->private;
@@ -618,7 +627,7 @@ static void pcl812_ai_setup_next_dma(struct comedi_device *dev, 
	struct pcl812_private *devpriv = dev->private;

	struct pcl812_dma_desc *dma;



	disable_dma(devpriv->dma);

	pcl812_isadma_disable(devpriv->dma);



	devpriv->cur_dma = 1 - devpriv->cur_dma;

	dma = &devpriv->dma_desc[devpriv->cur_dma];
@@ -980,7 +989,7 @@ static int pcl812_ai_cancel(struct comedi_device *dev, 
	struct pcl812_private *devpriv = dev->private;



	if (devpriv->ai_dma)

		disable_dma(devpriv->dma);

		pcl812_isadma_disable(devpriv->dma);



	outb(devpriv->mode_reg_int | PCL812_CTRL_DISABLE_TRIG,

	     dev->iobase + PCL812_CTRL_REG);